2.txt

一段用C++开发的代码

USHORT checksum(USHORT *buffer, int size)
{
　unsigned long cksum=0;
　while(size >1)
　{
　　cksum+=*buffer++;
　　size -=sizeof(USHORT);
　}
　if(size )
　{
　　cksum += *(UCHAR*)buffer;
　}
　cksum = (cksum >> 16) + (cksum & 0xffff);
　cksum += (cksum >>16);
　return (USHORT)(~cksum);
}